Transition Metal Cooperative Lewis Pairs Using Platinum(0) Diphosphine Monocarbonyl Complexes as Lewis bases

• Published in: Organometallics Vol. 39; no. 3; pp. 468 - 477
• Main Authors: Mistry, Krishna, Pringle, Paul G, Sparkes, Hazel A, Wass, Duncan F
• Format: Journal Article
• Language: English
• Published: American Chemical Society 10.02.2020
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/acs.organomet.9b00568

The platinum(0)-diphosphine complex [Pt­(CO)­(L1)] (3, where L1 = 1,2-C6H4(CH2PtBu2)2) and its diphosphinite analogue [Pt­(CO)­(L2)] (11, where L2 = 1,2-C6H4(OPtBu2)2) act as Lewis bases in conjunction with the main group Lewis acid B­(C6F5)3 to form frustrated or cooperative Lewis pairs. These systems activate dihydrogen, ethene/carbon monoxide, and phenylacetylene, leading to products that depend on the exact ligand used. These subtle changes to ligand structure influence reactivity, most notably in hydrogen activation where a variety of dinuclear species of the type [(diphos)­Pt­(μ-H)3Pt­(diphos)]+ or [(diphos)­Pt­(μ-H)­(μ-CO)­Pt­(diphos)]+ are observed. Activation of ethene with the Lewis pair leads to a previously reported coupling product and the mechanism is probed. The basicity of [Pt­(CO)­(L)] is demonstrated by deprotonation of phenylacetylene. Preliminary studies with an analogous palladium complex [Pd­(CO)­(L1)] 33 suggests related chemistry may be exploited for this metal. These results provide further examples of cooperative Lewis pair behavior in which one of the components is based on a transition metal complex.